Electric furnace for metallurgical purposes.



P. GIROD. BLEUTRIU FURNAGE FOB. METALLUBGIGL PURPOSES. Arrmoyrrox rILnnmso. no. 1905.

921,228. Patented May 11, 1909.

2 SHEETS-SHEET 1` Figi.

P. GIROD.

ELEGTEIG FURNAGE POB. METALLURGICAL PUBPGBES.

APPLIUATION FILED DEG. zo. 1905.

'921 ,228. Patented May 11, 1909.

2 SHEETS-SHEET 2` A Fig@ PA illlil NT (l F FIC lil.

lAUL GlROD, F UGlNl, l'lltANGl.

ELECTRIC FURNACE FOR METALLURGICAL PURPOSES.

T o all whom it may concern.'

' Be it known that 1, PAUL Guion, residing at Ugine, Savoie, France,have invented a new and useful Improvement in Electric receiver of thematerial to e melted or ofthe molten material.

This nventionhas for its object an electric `furnace for the manufactureof steel or soft metal in which one ofthe electrodes is replaced bv apole piece embedded in the furnace heart in such a manner that it maynot be ex osed to too great a temperature and that t e metal in contactwith 1t may be soliditied to an extent determined by experience. .Thispole may be formed of graphite ormetal or of any other suitableconducting substance, its interior may or may not be cooled.

, The accompanyin r drawingr illustrates two furnaces constructs inaccordance with this invention.

In this drawing: Figure 1 is a view in longitudinal section through a'furnace construct ed in accordance with the present invention.

exhibiting the same as it appears when empty. lrig. 2 is ahorizontalsectional view of t e same. Fig. 3 is a view similar to Fig.Lexhibiting the furnace at work. Fig. 4 is a view in longitudinalsection of a modiiied form of furnace. Fig, 5 is a horizontal sectionalview of the furnace shown in Fig. 4.

The rectangular furnace consists ofa metal frame, mounted on a pair oftrunnions 1, carried by su ports 2, which allow the furnace to be tilte(yby hand or by suitable mechan- The bottom 3 (provided as shown in Fig.2 with a laterally projecting portion 4, which serves to introduce thecurrent) carries two electrodes 5 and 6, embedded in frames 7 and 8,formed of an le irons furthe purpose of insuringbetter eectric contactwith the bottom These electrodes are surrounded by mason 9 and 10.formed of refractory bricks, pre erably of magnesia oralumin'oussilicates, because such bricks, when exposed to heat, do not becomeappreciably conduct- Specication of Letters Patent.

Application led December 530, 1905.

Patented May 1.1, 1909.

Serial No. 292,61'7...

Us... ive. The remainder of the i'ul nace is bricks or oi' the minerallo be treated or of any other materials fulfilling the desired object.

A simple or multiple movable electrode 11 ma be moved by hand ormechanically in suc 1 a manner as to he lowered into the inte ri'or ofthe furnace. i

The tapping holes land 13, shown in dots in Fig. 1, are arranged atdifferent levels either at the same side of the furnace or on oppositesides. At this point the refractory mass is made thicker as shown inFig. 2. This thicker portion is arranged in such a manner that it isossible to remove the part of the metal Whic surrounds it and'to thus relace the tapping holes `which it bears.

fit ybe desired for example to manufacture soft ferro-chrome, theelectrodes 5 and 6 are preferably merely composed of blocks of graphite.It Wilbe necessary therefore to cover them with a layer of metal for thepurpose of preventing their contact with the metal in a state of fusion.For this )urpose the ferro-chrome may be cast into t e cavi; tics ormelted in situ by means of the electric current or again by merelyplacing pieces of ferro-chrome above these electrodes.

,ln order to commence working the furnace, number of small pieces ofcarbon or of metal are arranged upon the bottom between the electrodos 5and 6 which arc covcrcd with cast metal or with small pieces of themanufactured product. T he upper electrode is then lowered and an arc isformed, the furnace is now charged, the material fuses and the fusedcharge and the slag form al rcsistancc, which usually causes theextinction of the are. the electrodes have been previously iilled witheast metal which has solidified the heat at this point is notsufficiently great to again fuse the metal; if, on the contrary, piecesof ferro-chrome or otlu L" products have been placed in the cavities forstarting the furnace, the metal in. the process of formation flows intothe said cavities and,

in view of the distance of the cavities from the main source of heut,amalgamates all the pieces previously introduced into one andsolidifiies on top of the electrodes. On

then entirely surrounded w1th masonry as shown 1n Figs. 1 and 2, formedeither oil' refractory the other hand, the size of the electrodes, andtherefore of the solidified metal, is made sufficiently' large that noheating by resistance takes place as this would cause the fusion of themetal. We have therefore a furnace with one or more uppe'r electrodesand one or more lower electrodes, the por tion of the lower electrodesin contact with the metal in fusion being in this case of the same metalas that which is beingr fused, ferro-chrome for example. In such afurnace therefore the carbon of the lower electrodes is never in contactwith the fused. metal and the upper electrode is regulated. in such amanner that it also does not touch the fused metal, but only the slagformed by the fluxes and the fused ore.

Fig. 3 shows the furnace at work. The

electrode 11 is immersed in the layer of slag 16, floating on the layer17 of fused metal. which covers the deposit 18, 19 of metal solidifiedat the lower electrodes 5 and 6.

The furnace thus constituted may work with a continuous or alternatingrcurrent etc. and at various voltages; one or more upper electrodes formone of the poles, and one or more electrodes, embedded in the masonryand protected by a layer of solidified metal, the other pole.

'l he lower electrodes may be rendered electrically independent of thehearth, by forming in the masonry a space for the assage of the electricleads and by insulating these leads in their passage through the sheetmetal bottom In this case the different electrodes may be connectedtogether in parallel or inseries. The electrodes embedded in the masonrymay also be placed at the sides of the furnace, how ever, they shouldalways be arranged in such a manner that the metal in their neighborhoodmay be solidified, that is to say, they should not be too near to theupper electrode.

The regulation of the temperature in the furnace moreover allows thezone of fusion to be limited.

'The metal and slag may be separatelyT tapped through holes arranged atdifferent levels if necessary or at the same time through a single hole.

The furnace may Without departing from this invention be a fixed one andit may if necessary be provided with a cover.

Figs. 4 and 5 show an oscillating circular furnace, especially designedfor the man facture of steel, cast iron. etc. `In this case the poleembedded in the masonry 20 is preferably formed of a cast iron ring 2l,provided with a water circulation 22. This ring becomes immediatelycovered with a layer 23 of solidified metal which then itself .leads thecurrent to the metal 24 in a state of fusion. The upper pole is formedof one or several electrodes 25 and the current passes through the slag26 and the fused ore.

As above stated, the electric lead embedded in. the masonry may equallywell be arranged at the sides or anywhere else, either by means of acircular continuous ring, as is the case in this furnace, or by means ofseparate electrodes, the said'electrodes being formed either of castiron, graphite, or of any other conductin material. It is sufficientmerely that tiey are always placed in such a manner as not to attain toohigh a degree of tem erature which Vwould melt the metal whic isintended to serve as a connection between the 'fused metal and the saidelectrodes. The slag serves as a resistance between the fused metal andthe electrodes. The furnace may moreover be used e uall as a simple arcfurnace by causing the e eetrode to project above the slag.

The manufacture of steel and of cast iron takes place in exactly thesame manner as in the usual methods of manufacture; refiningdecarbonization, desulfurizing, dephos horizing etc. may take place byany o the usual methods.

The voltage is chosen in a suitable manner for each manufacture; incertain cases it maybe fairly lour andthe la er of slag above the fusedmetal be extreme y thin; in other cases it is.made higher if theresistance be greater.

Having thus fully described my invention, what I claim is: l

l. An electric metallurgical furnace comprisin alower electrode, meansfor causin part o the metal to unite with the same, an an upperelectrode held in contact with the flux ut out of contact with the fusedmetal.

2. An electric furnace having opposed that portion of one of theelectrodes in contact with the metal in fusion being of the same metalas that which is being fused, and the other'electrode being adjustablewhereby it ma be kept out of contact with the fused meta and in contactonl`5T with the slag formed by the fluxes and the fused ore.

5. An electric furnace embodying op osed upper and lower electrodes andforme with a metal-receivin cavity at the end of one of the electrodes,t e other electrode being arranged to remain in Contact with the slag [ntestimony whereof l have signed this formed by the fluxes and the fusedore. l specification in the presence of two subscrib- 6. All electricfurnace embodying upper' irg Witnesses. and lower electrodes out ofvertical aline- PAUL' GIROD. ment, the lower electrode being annular,and Witnesses:

the furnace having e, metal-receiving clieml A. NEYRET,

ber over said lower annular electrode. T. W. MURTON.

